Wiper pivot shaft and wiper apparatus

ABSTRACT

In a wiper apparatus of a vehicle, an intermediate support portion 14 of a wiper pivot shaft (10) is inserted into a pivot holder (12) fixed on a vehicle body and is thus supported. One side surface (23) of a flange portion (24), which is located between the support portion (14) and a link-lever-attaching portion (22) which is one end portion of the shaft (10), is opposed to one opening end of the pivot holder (12) to thereby determine the amount of insertion of the shaft (10). One end portion of the link lever (20) is press-fitted to the periphery of the link-lever-attaching portion (22). At this time, the link lever (20) abuts the other side surface (25) of the flange portion (24) to thereby determine the amount of press fit. One end portion of a wiper arm (32) is fitted to the periphery of a wiper-arm-mating portion (22) which is the other end portion of the shaft (10). Thus, the diameter of the link-lever-attaching portion (22) can be set appropriately, while the shaft has a necessary and sufficient strength as a whole. Also, high assembly accuracy is obtained.

TECHNICAL FIELD

The present invention relates to a wiper pivot shaft used in the wiperapparatus of a vehicle or the like and to a wiper apparatus using thesame.

BACKGROUND ART

A wiper apparatus is equipped with a wiper pivot shaft (shaft). Theintermediate portion of the shaft is inserted into a pivot holder sothat the shaft is rotatable supported. The pivot holder is fixed onto avehicle body. A link lever is attached to one end portion of the shaft,while a wiper arm is attached to the other end portion of the shaft. Amotor is connected to the link lever via a link mechanism, and a wiperblade is retained on the wiper arm. The link mechanism converts therotary motion of the motor to the reciprocatively rotational motion(swinging motion) of the link lever. A reciprocatively rotational torqueis transmitted to the shaft through the reciprocative rotation of thelink lever, so that the shaft causes the wiper arm to reciprocativelyrotate (swing) along a glass surface. As the wiper arm reciprocativelyrotates, the wiper blade wipes the glass surface.

As shown in FIG. 9(A), a first end portion 102 of a shaft 100 has asmaller diameter and serves as a link-lever-attaching portion. A step106 is formed between the first end portion 102 and an intermediateportion 104. The outer circumferential surface of the one end portion102 is knurled. An engagement hole 110 is formed in a link lever 108 atone end portion thereof. As shown in FIG. 9(B), the link lever 108 isdriven onto the first end portion 102 of the shaft 100, and the firstend portion 102 is press-fitted into the engagement hole 110 until thehole edge portion of the link lever 108 abuts the step 106. After thepress fit, the tip end of the first end portion 102 projecting from theengagement hole 110 is crimped (the crimped portion is denoted bynumeral 112). Thus, the link lever 108 is attached to the one endportion 102 of the shaft 100.

Such a configuration is made public in Japanese Utility ModelApplication Laid-Open Nos. 4-113262, 4-113263, and 4-113264.

A large load is expected to be imposed on the wiper arm. The link lever108 needs to obtain such an anti-slip torque (joining force) as not toslip with respect to the one end portion 102 of the shaft 100 within theexpected range of load. A slip disables a wiper.

When the anti-slip torque is compared between different diameters A(knurl diameters A) of the one end portion 102 of the shaft 100, it isfound that the larger the knurl diameter A is, the larger anti-sliptorque is obtained. The knurl diameter A is set according to a requiredanti-slip torque.

On the other hand, when the step 106 located between the intermediateportion 104 and the first end portion 102 is small, the surface ofcontact between the step 106 and the link lever 108 becomes small. Whenthe contact surface is small, the hole edge portion of the engagementhole 110 of the link lever 108 bites the intermediate portion 104 of theshaft 100 upon press fit of the link lever 108. As a result of thisbite, the length of the intermediate portion 104 of the shaft 100becomes short, and consequently the installed position of the link lever108 becomes different from an expected position. That is, after the linklever 108 is press-fitted, the axial dimension of the shaft 100 is indanger of becoming different than what it was before the press-fitting.Further, for assemblies of the shaft 100 and the link lever 108 obtainedby press-fitting the shaft 100 into the link lever 108, the amount ofthe link lever 108 biting the intermediate portion 104 may differ,resulting in potential variations in the axial dimension of the shaft100.

Thus, the step 106 must have such a size as to prevent such a problem.

However, when the knurl diameter A to be set is large, the diameter B ofthe intermediate portion 104 of the shaft 100 must also be made large;otherwise, the step 106 having a required size will not be secured. Whenthe diameter B of the intermediate portion 104 of the shaft 100 is madelarge in order to secure the step 106 having a required size, thediameter B becomes unnecessarily large. As a result, the shaft 100 isunnecessarily overweighted at the intermediate portion 104 and is alsounnecessarily strengthened.

As shown in FIG. 10, when the step 106 is small, the step 106 fails toreceive the link lever 108 in a proper posture upon press fit of thelink lever 108, so that there arises a misalignment between the axis ofthe shaft 100 and the axis of the engagement hole 110. Thus, the linklever 108 fails to assume the posture represented by a solid line inFIG. 10, and inclines as represented by a two-dot-and dash line in FIG.10, resulting in impaired perpendicularity of an angle θ between thelink lever 108 and the shaft 100. When perpendicularity of the angle θis impaired, the axis of the shaft 100 does not become parallel to theaxis of a pivot 118, which is provided at an end portion of the linklever 108 opposed to the engagement hole 110 and is connected to theaforementioned link mechanism so as to reciprocatively rotate the linklever 108. Thus, as the link lever 108 rotates reciprocatively, thereoccurs an uneven sliding contact between one opening end of a pivotholder 114, into which the intermediate portion of the shaft 100 isinserted, and the link lever 108 opposed thereto. When this unevensliding contact occurs, the anti-slide torque becomes unstable, and thethrust play of the shaft 100 also becomes unstable.

Also, when the link lever 108 inclines as represented by thetwo-dot-and-dash line in FIG. 10 with a resultant impairment ofperpendicularity of the angle θ, there becomes unstable a dimension Lbetween a mating surface 117 for attachment to a vehicle body of anattachment flange 116, which is formed on the periphery of the pivotholder 114 in order to fix the pivot holder 114 onto the vehicle body,and a pivotal point 119 of the pivot 118 of the link liver 108,resulting in a failure to obtain a predetermined wiping angle of a wiperarm 108.

Thus, a plain washer 120 and a wave washer 122 are interposed betweenthe pivot holder 114 and the link lever 108 so as to stabilize theanti-slip torque and the thrust play of the shaft 100.

Japanese Utility Model Publication No. 3011446 introduces a shaft havinga flange portion which contacts a link lever. However, the relationbetween the flange portion and a pivot holder is not considered at all.

DISCLOSURE OF THE INVENTION

In view of the foregoing fact, it is an object of the present inventionto provide a wiper arm shaft allowing the diameter of thelink-lever-attaching portion of the shaft to be set appropriately withthe shaft having a necessary and sufficient strength as a whole andproviding high assembly accuracy to thereby stabilize the axialdimension of the shaft without the axial dimension after attachment of alink lever to the shaft being made different from that before theattachment, as well as to provide a wiper apparatus.

The present invention is a wiper apparatus including:

a cylindrical pivot holder having an opening at both ends; a wiper pivotshaft having a support portion, a link-leverage attaching portion, awiper-arm mating portion, and a flange portion, the support portionforming an intermediate portion of the shaft supported in thecylindrical pivot holder, and having a predetermined diameter D;

the link-lever attaching portion forming a first end portion of theshaft projecting from a first opening of the pivot holder, and having apredetermined diameter C greater than the predetermined diameter D ofthe support portion;

the wiper-arm mating portion forming a second end portion of the shaftprojecting from a second open end of the pivot holder; and the flangeportion is provided between the support portion and the link-leverattaching portion, and has a diameter greater than the diameter D of thesupport portion and the diameter C of the link-lever attaching portion,and projects perpendicularly to an axial direction of the shaft, and thefirst end surface of the flange portion at a link-lever attaching sideportion is substantially flat and a second end surface of the flangeportion is supported at the first opening of the pivot holder;

a link lever that abuts the flat end surface of the flange portion atthe link lever attaching portion of the flange portion and which is fitonto a periphery of said link-lever attaching portion in order totransmit a reciprocatively rotational torque to said wiper shaft; and

a wiper arm attached to said wiper arm mating portion so as toreciprocatively rotate together with the wiper pivot shaft.

According to the present invention, the link lever is fitted onto theouter peripheral surface of the link-lever-attaching portion of theshaft; the second end surface of the flange portion is supported at thefirst opening of the pivot holder to thereby determine the amount ofinsertion of the shaft into the pivot holder; and the flat leverattaching side portion of the flange portion abuts the link lever tothereby determine the amount of fit of the link lever.

For example, the link-lever-attaching portion is knurled, and the linklever is press-fitted thereto.

The diameter of the link-lever-attaching portion needs to beappropriately set so that the link lever obtains such an anti-sliptorque (joining force) as not to slip with respect to thelink-lever-attaching portion of the shaft, to thereby prevent the wiperfrom becoming disabled. In the present invention, even when the diameterof the link-lever-attaching portion to be set is large, the first endside surface of the flange portion which abuts the link lever can assumea sufficiently and appropriately large contact surface withoutincreasing the diameter of the support portion of the shaft. Throughsecurement of a sufficiently and appropriately large contact surface,when the link lever is attached to the shaft, the link lever can beprevented from biting the flange portion or the support portion, and theinstalled position of the link lever matches a previously set positionalong the axial direction of the shaft.

Accordingly, the diameter of the link-lever-attaching portion of theshaft can be set appropriately, while the shaft has a necessary andsufficient strength as a whole. Also, the axial dimension of the shaftcan be stabilized without the axial dimension after attachment of a linklever to the shaft being made different from that before the attachment.

In addition, the following high assembly accuracy is obtained.

That is, the other side surface of the flange portion capable ofsecuring a sufficiently large contact surface receives the link lever ina proper posture when the link lever is fitted. Thus, a high degree ofperpendicularity is obtained for the angle θ between the link lever andthe shaft. Also, the flange portion has a strength against press fit ofthe shaft into the link lever, so that the one side surface of theflange portion does not vary dimensionally in the axial direction. Thisprevents uneven sliding contact on the link lever side of the pivotholder, i.e. between the one opening end of the pivot holder and the oneside surface of the flange portion opposed thereto. Accordingly, theanti-slide torque is stabilized, and the thrust play of the shaft isalso stabilized. As a result, there is no need to interpose a wavewasher or the like on the link lever side of the pivot holder, i.e.between the one opening end of the pivot holder and the one side surfaceof the flange portion opposed thereto.

In addition to attainment of a high degree of perpendicularity for theangle θ, the other side surface of the flange portion abuts the linklever to thereby determine the amount of fit of the link lever 20, andthe one side surface of the flange portion is opposed to the one openingend of the pivot holder to thereby determine the amount of insertion ofthe shaft. Thus, the axial dimension of the shaft between the pivotholder and the link lever is accurately stabilized, so that the wipingangle of the wiper arm can assume a predetermined angle.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts to a first embodiment of a wiper pivot shaft and a wiperapparatus of the present invention and is a partially sectioned andexploded front view of the main portion thereof.

FIG. 2 is a partially sectioned front view of the first embodimentshowing the assembled state of the main portion thereof.

FIG. 3 is a schematic configurational view showing a wiper apparatus ofthe present invention.

FIG. 4 and shows wiper pivot shafts according to the first embodimenthaving link-lever-attaching portions of different diameters, whereinFIG. 4(A) is a front view of the case where the diameter of thelink-lever-attaching portion is identical to that of the supportportion, FIG. 4 (B) is a front view of the case where the diameter ofthe link-lever-attaching portion is smaller than that of the supportportion, and FIG. 4(C) is a front view of the case where the diameter ofthe link-lever-attaching portion is greater than that of the supportportion.

FIG. 5 depicts a second embodiment of the wiper pivot shaft and thewiper apparatus of the present invention and is a partially sectionedand exploded front view of the main portion thereof.

FIG. 6 depicts the second embodiment and is a partially sectioned frontview of the second embodiment showing the assembled state of the mainportion thereof.

FIG. 7 depicts a third embodiment of the wiper pivot shaft and the wiperapparatus of the present invention and is a partially sectioned andexploded front view of the main portion thereof.

FIG. 8 depicts a partially sectioned front view of the third embodimentshowing the assembled state of the main portion thereof.

FIG. 9 shows prior art and shows a wiper pivot shaft and a link lever tobe attached to one end portion thereof, wherein FIG. 9(A) is a frontview showing the state before the link lever is attached to the one endportion of the shaft, and FIG. 9(B) is a front view showing the statethat the link lever is attached to the one end portion of the shaft.

FIG. 10 relates to the prior art and is a partially sectioned front viewshowing the relation among a shaft, a link lever, and a pivot holder.

BEST MODE FOR CARRYING OUT THE INVENTION

A wiper pivot shaft and a wiper apparatus according to the presentinvention will now be described in detail with reference to the appendeddrawings.

First, a first embodiment will be described with reference to FIGS. 1 to4.

As shown in FIGS. 1 and 2, the wiper apparatus of a vehicle has a wiperpivot shaft (hereinafter, referred to as a shaft) 10. The intermediateportion (a support portion 14) of the shaft 10 is inserted into a pivotholder 12, and the shaft 10 is thus supported. The pivot holder 12 iscylindrically formed. An attachment flange 16 is projectingly formed onthe outer circumferential surface of the pivot holder 12 and is fixedlyattached onto a vehicle body 250 through use of a bolt or the like. Apair of sleeves 18 are interposed between the inner circumferentialsurface of the pivot holder 12 and the outer circumferential surface ofthe shaft 10. Both the sleeves 18 are located opposingly apart from eachother in the axial direction of the shaft 10. The outer circumferentialsurface of the support portion 14 of the shaft 10 slidably contacts theinner circumferential surfaces of the sleeves 18, so that the shaft 10is rotatable.

The slidably contacting outer circumferential surface of the shaft 10 islubricated with grease. The gap between the outer circumferentialsurface of the support portion 14 and the inner circumferential surfaceof the pivot holder 12 located between the opposed ends of the sleeves18 serves as a grease pocket (lubricating fluid pocket). In the casewhere the shaft 10 is made of a metal, and the pivot holder 12 is alsomade of a metal, the sleeves 18 are made of a synthetic resin. Thus, theouter circumferential surface of the support portion 14 of the shaft 10slidably contacts the inner circumferential surfaces of the sleeves 18,so that sliding contact is made between a part made of a metal and apart made of a synthetic resin to thereby reduce wear or the like whichwould be induced from sliding contact between metallic parts. In thecase where the shaft is made of a metal and the pivot holder 12 is madeof a synthetic resin, sliding contact between metallic parts can beprevented even if the outer circumferential surface of the shaft 10 isbrought in direct sliding contact with the inner circumferential surfaceof the pivot holder 12. Therefore, the sleeves 18 are unnecessary solong as the prevention of sliding contact between metallic parts isconcerned.

A first end portion (a link-lever-attaching portion 22) of the shaft 10projects from a first opening 254 of the pivot holder 12, and the linklever 20 is attached thereto. The outer circumferential surface of thelink-lever-attaching portion 22 is knurled. A flange portion(flange-shaped portion) 24 is integrally provided on the shaft 10between the link-lever-attaching portion 22 and the support portion 14,the flange portion 24 having a diameter larger than those of both theportions. An engagement hole 26 is formed in one end portion of the linklever 20. A second end surface 23 of the flange portion 24 is supportedat the first opening of the pivot holder 12. The shaft is inserted fromthe other end portion thereof into the pivot holder 12 through the oneopening end of the pivot holder 12. The link lever 20 is driven onto thelink-lever-attaching portion 22, and thus the link-lever-attachingportion 22 is press-fitted into the engagement hole 26, so that the linklever 20 is fitted onto the periphery of the link-lever-attachingportion 22. During this press fit, the link-lever-attaching portion 22is press-fitted into the engagement hole 26 until the hole edge portionof the engagement hole 26 of the link lever 20 abuts the flat endsurface 25 on the link-lever-attaching side of the flange portion 24.Thus, the amount of fit (the amount of press fit) of the link lever 20onto the link-lever-attaching portion 22 is limited. The tip end of thelink-lever-attaching portion 22 projecting from the engagement hole 26is crimped (the crimped portion is denoted by numeral 28 in FIG. 2).

As shown in FIG. 3, a pivot 30 (see also FIG. 2), on which a link 200 ispivoted, is projectingly provided at the other end portion of the linklever 20 on a side surface 21 facing the side of the flange portion 24.A motor 204 is connected to the link lever 20 via a link mechanism 202including the link 200. The link mechanism 202 converts the rotarymotion of the motor 204 to the reciprocatively rotational motion(swinging motion) of the link lever 20 with the shaft 10 serving as areciprocative rotational shaft (swinging shaft).

When the link lever 20 is attached to the link-lever-attaching portion22, the link lever 20 is connected to the link-lever-attaching portion22 such that the link lever 20 can transmit a reciprocatively rotationaltorque to the link-lever-attaching portion 22 as the link lever 20 makesa reciprocatively rotational motion.

As shown in FIG. 2, the other end portion (a wiper-arm-mating portion34) of the shaft 10 projects from a second opening 256 of the pivotholder 12. A wiper arm 32 is attached to the projecting wiper-arm-matingportion 34. The wiper-arm-mating portion 34 has a taper portion 36,which is located on the side of the support portion 14 and tapers offtoward the side opposite to the support portion 14, and an externalthread portion 38, which is formed on the side opposite to the supportportion 14. The outer circumferential surface of the taper portion 36 isknurled. The base end portion of the wiper arm 32 is fitted to the taperportion 36, and a nut 206 is screw-engaged with the external threadportion 38 to thereby fasten the base end portion of the wiper arm 32.Thus, the wiper arm 32 is connected to the wiper-arm-mating portion 34so as to be reciprocatively rotatable together with the shaft 10. Asshown in FIG. 3, the wiper arm 32 is reciprocatively rotated (swung)along a glass surface 208 of the vehicle in the directions of arrow A.As shown in the same figure, a wiper blade 210 is retained to the wiperarm 32, so that the glass surface 208 is wiped by the wiper blade 210 asthe wiper arm 32 rotates reciprocatively.

For the shaft 10, a wave washer (wave washer), together with a plainwasher 42, is interposed between the one opening end of the pivot holder12 and the flange portion 24. The wave washer 40 is located on the sideof the flange portion 24, while the plain washer 42 is located on theside of the pivot holder 12. The flange portion 24 abuts the firstopening of the pivot holder 12 via the wave washer 40 and the plainwasher 42 to thereby determine the amount of insertion of the shaft 10into the pivot holder 12. Also, the wave washer 40 limits the axialmovement of the shaft 10.

Also, an engagement groove 48 is formed in the shaft 10 between thesupport portion 14 and the wiper-arm-mating portion 34. A C-ring(retaining ring) 44 serving as a retaining member is fitted into theengagement groove 48. A plain washer 46, through which the shaft 10 isinserted, is interposed between the C-ring 44 and the second opening ofthe pivot holder 12. The C-ring 44 abuts the second opening of the pivotholder 12 via the pivot holder 12 to thereby prevent the shaft 10 fromcoming off.

According to the above-described configuration, the link lever 20 isdriven by the motor 204 and is reciprocatively rotated via the linkmechanism 202. Also, a reciprocatively rotational torque is transmittedfrom the link lever 20 to the shaft 10, and thus the wiper arm 32 isreciprocatively rotated, so that the wiper blade 210 wipes the glasssurface 208.

When the link lever 20 is attached to the link-lever-attaching portion22 of the shaft 10, the link lever 20 is driven onto thelink-lever-attaching portion 22 until the link lever 20 abuts the flatend (first end); surface 25 of the flange portion 24. Thus, thelink-lever-attaching portion 22 is press-fitted into the engagement hole26 of the link lever 20 and is then crimped. At this time, the first endsurface 25 of the flange portion 24 receives a pressing force associatedwith the press fit and crimping.

Diameter E of the flange portion 24 is rendered larger than bothdiameter D of the support portion 14 and diameter C of thelink-lever-attaching portion 22. When the diameter (knurl diameter) C ofthe link-lever-attaching portion is smaller than the diameter D of thesupport portion 14 (when C<D, particularly, when their difference issmall) as shown in FIG. 4(B), or when the diameter C of thelink-lever-attaching portion 22 is identical to the diameter D of thesupport portion 14 (when C=D) as shown in FIG. 4(A), or further when thediameter C of the link-lever-attaching portion 22 is larger than thediameter D of the support portion 14 (C>D) as shown in FIG. (C), thediameter E of the flange portion 24 can be rendered sufficiently largeras compared with the diameter C of the link-lever-attaching portion 22,to thereby render the first end surface 25 of the flange portion 24large.

On the other hand, a large load is expected to be imposed on the wiperarm 32. Thus, the diameter C of the link-lever-attaching portion 22 mustbe set such that even in such a case, the link lever 20 obtains such ananti-slip torque (joining force) as not to slip with respect to thelink-lever-attaching portion 22, to thereby prevent the wiper frombecoming disabled.

According to the present embodiment, even when the diameter C of thelink-lever-attaching portion 22 to be set is large, the contact surfaceof the flange portion 24 with the link lever 20 can be renderedsufficiently and appropriately large without increasing the diameter Dof the support portion 14 of the shaft 10. Through securement of thesufficiently and appropriately large contact surface, when first endsurface 25 of the flange portion 24 receives a pressing force associatedwith press fit and crimping, the link lever 20 can be prevented frombiting the flange portion 24 or the support portion 14. Thus, the amountof press fit accurately matches a predetermined amount of press fit.Accordingly, the installed position of the link lever 20 highlyaccurately matches a predetermined set position along the axialdirection of the shaft 10.

Accordingly, the diameter C of the link-lever-attaching portion 22 ofthe shaft 10 can be set appropriately, while the shaft 10 has anecessary and sufficient strength as a whole. Also, the axial dimensionof the shaft 10 can be stabilized without the axial dimension afterattachment of the link lever 20 to the shaft 10 being made differentfrom that before the attachment.

In addition, the following high assembly accuracy is obtained.

That is, the first end side surface 25 of the flange portion 24 capableof securing a sufficiently large contact surface receives the link lever20 in a proper posture when the link lever 20 is press-fitted. Thus, theaxis of the shaft 10 and the axis of the engagement hole 26 of the linklever 20 align with each other, so that a high degree ofperpendicularity is obtained for the angle θ between the link lever andthe shaft. Through attainment of a high degree of perpendicularity forthe angle θ, the axis of the shaft 10 accurately parallels the axis ofthe pivot 30 of the link lever 20. Accordingly, so long as the firstopening of the pivot holder 12 and the second end surface 23 of theflange portion 24 are respectively perpendicular to the axial direction,uneven sliding contact is prevented between the first opening of thepivot holder 12 and the second end surface 23 of the flange portion 24opposed thereto via the wave washer 40 and the plain washer 42.Accordingly, the anti-slide torque is stabilized, and the thrust play ofthe shaft 10 is also stabilized.

Also, since the amount of insertion of the shaft 20 is determinedthrough abutment of the second end surface 23 of the flange portion 24against the first opening of the pivot holder 12 via the wave washer 40and the plain washer 42, there becomes constant an axial dimension D1 ofthe shaft 10 between a mating surface 17 of the attachment flange 16 ofthe pivot holder 12 for attachment to the vehicle body 250 and thesecond end surface 23 of the flange portion 24. Also, the amount ofdriving the link lever 20 (amount of press fit) is stably determinedthrough abutment of the link lever 20 against the first end surface 25of the flange portion 24, so that there becomes constant an axialdimension D2 of the shaft 10 between the mating surface 17 of theattachment flange 16 and the side surface 21 of the link lever 20 facingon the side of the flange portion 24. The dimensions D1 and D2 arerendered constant, and an axial dimension D3 of the shaft 10 between themating surface 17 of the attachment flange 16 and a pivotal point 31 ofthe pivot 30 of the link lever 20 is stabilized to a previously setdimension. Thus, a predetermined wiping angle of the wiper arm 32 can beobtained.

The shaft 10 can not only be integrally machined through cutting butalso be cold-forged. Through employment of cold forging, raw materialcan be of a small diameter corresponding to the diameter D of thesupport portion 14, not a large diameter corresponding to the diameter Eof the flange portion 24. The support portion 14, the flange portion 24,and the link-lever-attaching portion 22, which respectively havepredetermined diameters, can be integrally manufactured from the rawmaterial, thereby realizing a reduction in cost.

Thus, the wiper apparatus attains high assembly accuracy.

Next, a second embodiment will be described with reference to FIGS. 5and 6.

In the present embodiment, the shaft 10 is made of a metal, and thepivot holder 12 is made of a metal such as aluminum. The sleeves 18 aremade of a synthetic resin.

In the above-described first embodiment, the wave washer 40 and theplain washer 42 are disposed on the shaft 10 to be interposed betweenthe first opening of the pivot holder 12 and the second end surface 23of the flange portion 24; however, as shown in FIG. 5, they are notprovided in the present embodiment. As shown in FIG. 6, the second endsurface 23 of the flange portion 24 directly abuts the first opening ofthe pivot holder 12 to thereby determine the amount of insertion of theshaft 10 into the pivot holder 12.

Further, in the above-described first embodiment, the C-ring 44 isfitted in the engagement groove 48 of the shaft 10 located between thesupport portion 14 and the wiper-arm-mating portion 34; however, asshown in FIG. 5, a teeth washer (toothed washer) 212 is provided as aretaining member in place of the C-ring 44 and the engagement groove 48.As shown in FIG. 6, the teeth washer 212 is pressfitted onto theperiphery of the shaft 10 and abuts the second opening of the pivotholder 12 via the plain washer 46. Through use of the teeth washer 212,the shaft 10 is prevented from coming off, and the axial play of theshaft 10 is prevented.

In view of the fact that through attainment of a high degree ofperpendicularity for the angle e between the link lever 20 and the shaft10, uneven sliding contact is prevented between the first opening end ofthe pivot holder 12 and the link lever 20 opposed thereto, as describedabove in the description of the first embodiment, in the configurationof the present embodiment, the second end surface 23 of the flangeportion 24 directly abuts the first opening of the pivot holder 12, thusomitting a wave washer and a plain washer from therebetween.

As a wave washer and a plain washer are omitted, the number of partsdecreases accordingly, so that costs are reduced.

As shown in FIG. 6, particularly, since the amount of insertion of theshaft 20 is determined through direct abutment of the second end surface23 of the flange portion 24 against the first opening of the pivotholder 12, there becomes further accurately constant the dimension D1between the mating surface 17 of the attachment flange 16 of the pivotholder 12 for attachment to the vehicle body 250 and the second endsurface 23 of the flange portion 24. Accordingly, there becomes furtheraccurately constant the dimension D2 between the mating surface 17 ofthe attachment flange 16 and the side surface 21 of the link lever 20located on the side of the flange portion 16. Also, the dimension D3between the mating surface 17 of the attachment flange 16 and thepivotal point 31 of the pivot 30 of the link lever 20 is stabilizedfurther accurately to a previously set dimension.

Next, a third embodiment will be described with reference to FIGS. 7 and8.

In the present embodiment, the shaft 10 is made of a metal, while thepivot holder is made of a synthetic resin.

In the first and second embodiments, the sleeves 18 are interposedbetween the pivot holder 12 and the shaft 10, and the outercircumferential surface of the shaft 10 slidably contacts the innercircumferential surfaces of the sleeves 18. However, in the presentembodiment, as shown in FIG. 7, no sleeve is present between the pivotholder 12 and the shaft 10. As shown in FIG. 8, the outercircumferential surface of the shaft 10 directly contacts the innercircumferential surface of the pivot holder 12 in a slidable manner.

Since the pivot holder 12 is made of a synthetic resin, while the shaft10 is made of a metal, even when no sleeve is provided therebetween, thesliding contact between the shaft 10 and the pivot holder 12 is freefrom problems of wear and sliding noise which would be induced from thesliding contact between metallic parts.

As shown in FIG. 7, a plurality of grooves 252 are formed in the innercircumferential surface of the pivot holder 12. The grooves 252 arecircumferentially arranged at predetermined intervals and extendelongatively along the axial direction of the pivot holder 12 from theaxially intermediate portion of the pivot holder 12 to the first openingof the pivot holder 12. The grooves 252 serve as grease pockets(lubricating fluid pockets) for grease with which the outercircumferential surface of the shaft 10 is lubricated.

Also, in the present embodiment, in view of the fact that as in thesecond embodiment, a high degree of perpendicularity is attained for theangle θ between the link lever 20 and the shaft 10, the second endsurface 23 of the flange portion 24 directly abuts the first opening ofthe pivot holder 12, thus omitting a wave washer and a plain washer fromtherebetween.

Thus, as in the second embodiment, there are further accurately obtainedthe dimension D1 between the mating surface 17 of the attachment flange16 of the pivot holder 12 for attachment to the vehicle body 250 and thesecond end surface 23 of the flange portion 24, and the dimension D2between the mating surface 17 of the attachment flange 16 and the sidesurface 21 of the link lever 20 located on the side of the flangeportion 24. Also, the dimension D3 between the mating surface 17 of theattachment flange 16 and the pivotal point 31 of the pivot 30 of thelink lever 20 is stabilized further accurately to a previously setdimension.

Further, the teeth washer 212 directly abuts the second opening of thepivot holder 12 without a plain washer being present between the teethwasher 212 and the second opening of the pivot holder 12.

When both of the shaft 10 and the pivot holder 12 are made of a metal asin the first and second embodiments, a plain washer 46 is interposedbetween the metallic C-ring 44 or the metallic teeth washer 212 and thepivot holder 12 in order to prevent metallic part-to-metallic partsliding contact between the C-ring 44 or the teeth washer 212 and thesecond opening of the pivot holder 12, thereby reducing wear and slidingnoise which would be induced from contact between metallic parts.

In the case where the pivot holder 12 is made of a synthetic resin as inthe present embodiment, even when the metallic teeth washer 212 isbrought in direct abutment against the second opening of the pivotholder 12, metal-to-synthetic resin contact is established between theteeth washer 212 and the second opening end of the pivot holder 12,thereby reducing wear and sliding noise which would be induced fromsliding contact between metallic parts.

A wave washer and a plain washer are omitted from between the firstopening of the pivot holder 12 and the second end surface 23 of theflange portion 24, and a plain washer is omitted from between the teethwasher 212 and the first opening of the pivot holder 12, the number ofparts further decreases, so that costs are further reduced.

Other features of structure, action, and effect of the second and thirdembodiments are similar to those of the first embodiment.

INDUSTRIAL APPLICABILITY

As described above, a wiper pivot shaft and a wiper apparatus accordingto the present invention are usefully applicable to a shaft fortransmitting a reciprocatively rotational torque from a link leverconnected to a motor via a link mechanism to a wiper arm retaining awiper blade as well as to a wiper apparatus for use in a vehicle or thelike for wiping a glass surface with a wiper blade through reciprocativerotation of a wiper arm along the glass surface.

What is claimed is:
 1. A wiper apparatus comprising:a cylindrical pivotholder made of a synthetic resin and having an axial hole including afirst opening at one end and a second opening at another end, the axialhole having a plurality of peripherally spaced grooves extending from anaxial direction intermediate portion of the pivot holder to the firstopening for containing lubricating fluid, each of said grooves having auniform depth along its length; a wiper pivot shaft made of a metal,having a support portion, a link-lever-attaching portion, awiper-arm-mating portion, and a flange portion, said wiper pivot shaftbeing inserted through the axial hole of said pivot holder, and saidsupport portion, said link-lever-attaching portion, saidwiper-arm-mating portion and said flange portion being formed integrallyby cold forging, said support portion forming an intermediate portion ofsaid shaft being supported in said pivot holder, and having apredetermined diameter D; said link-lever-attaching portion forming afirst end portion of said shaft, projecting from the first opening ofsaid pivot holder, and having a predetermined diameter C greater thanthe predetermined diameter D of said support portion; saidwiper-arm-mating portion forming a second end portion of said shaft andprojecting from the second opening of said pivot holder; said flangeportion being provided between said support portion and saidlink-lever-attaching portion, said flange portion having a diameter Egreater than the diameter of the raw material constituting said wiperpivot shaft before the cold forging and the diameter C of saidlink-lever-attaching portion, and projecting perpendicularly in an axialdirection of said shaft as a result of the cold forging, wherein a firstend surface of said flange portion opposes the first opening of saidpivot holder; a link lever that is adjacent to another end surface ofsaid flange portion, said link lever being fitted onto a periphery ofsaid link-lever-attaching portion in order to transmit a reciprocativelyrotational torque to said wiper pivot shaft; and a wiper arm attached tosaid wiper-arm-mating portion so as to reciprocatively rotate togetherwith said wiper pivot shaft.
 2. A wiper apparatus as in claim 1, whereinthe second end surface of said flange portion directly abuts the firstopening of said pivot holder.
 3. A wiper apparatus as in claim 1,further comprising a retaining member fitted onto a periphery of saidshaft between said wiper-arm-mating portion and the second opening ofsaid pivot holder such that the retaining member faces the secondopening of said pivot holder, to thereby prevent said shaft from atleast one of angular and axial displacement.
 4. A wiper apparatus as inclaim 1, wherein the second end surface of said flange portion directlyabuts the first opening of said pivot holder, said apparatus furthercomprising a retaining member fitted to a periphery of said shaftbetween said wiper-arm-mating portion and the second opening of saidpivot holder and which directly abuts the second opening of said pivotholder, to thereby prevent said shaft from at least one of angular andaxial displacement.
 5. A wiper apparatus as in claim 4, wherein saidretaining member is a toothed washer.
 6. A wiper apparatus as in claim1, wherein an outer circumferential surface of said shaft slidablycontacts an inner circumferential surface of said pivot holder tothereby allow said shaft to rotate and form a groove in the innercircumferential surface of said pivot holder so as to serve as alubricating fluid pocket that contains a lubricating fluid forlubricating the slidably contacting outer circumferential surface ofsaid shaft.
 7. A wiper apparatus as in claim 1, wherein said pivotholder is fixed onto a vehicle body, said link lever is connected to amotor via a link mechanism, a rotary motion of the motor is converted tothe reciprocatively rotational motion of said link lever by the linkmechanism; andsaid wiper arm retains a wiper blade, and the wiper bladewipes a glass surface as said wiper arm reciprocatively rotates alongthe glass surface.
 8. A wiper apparatus as in claim 7, wherein anattachment flange is formed on said pivot holder, the attachment flangeattaches said pivot holder to the vehicle body.
 9. A wiper apparatus asin claim 7, wherein a first end portion of said link lever is attachedto said link-lever-attaching portion, and a pivot to be connected tosaid link mechanism is provided on the second end portion of said linklever.
 10. A wiper apparatus as in claim 1, wherein said link has anengagement hole formed therein; andsaid link-lever-attaching portion ispress-fitted into the engagement hole.
 11. A wiper apparatus as in claim10, wherein the link-lever-attaching portion is knurled.
 12. A wiperapparatus as in claim 1, wherein said wiper-arm-mating portion comprisesa tapered portion and an externally threaded portion and said wiper armis attached to said wiper-arm-mating portion through engagement of saidwiper arm with the tapered portion and through screw engagement of a nutwith the externally threaded portion.